1. Field of the Invention
The present invention relates to a light resistant colorant and a composition containing the colorant. More particularly, the present invention relates to a light resistant colorant obtained by coupling a light resistant material with a dye or a pigment, and a composition containing the colorant.
2. Description of the Related Art
Generally, colorants are substances that develop their colors by selectively absorbing or reflecting visible light. Colorants are widely used in a variety of coloration industries, for example, in foods, drugs, cosmetics, paints, ink-jet inks, toners, fibers, leathers, plastics coloration, rubbers coloration, furniture fabrication, textile printing, paper-making, and ceramics. There are two types of colorants: dyes and pigments. Dyes are colored substances that are dissolved and mono-dispersed in water or oil and are bonded to molecules of substrates, such as fibers, for coloration. Pigments are not dissolved in water or oil, and thus, pigment powders form opaque colored films on the surfaces of substrates. Conventionally, dyes provide a wide color gamut and a bright and clear color. However, decoloration or discoloration by light and running of colors in water or organic solvents are likely to occur. Therefore, dyes have poor light and water resistance. On the other hand, pigments have better light and water resistance than dyes. However, when pigments are exposed to ultraviolet light from the sun or the like for a long time, they may become discolored. In addition, pigments provide a narrower color gamut and types of pigments are not diversified, relative to dyes. For these reasons, light stabilizers are separately added to compositions containing colorants in an attempt to improve light resistance of the compositions. However, such light stabilizers lower the stability of the compositions, thus generating precipitates. Therefore, it is difficult to ensure consistencies of the compositions. In addition, when the compositions are projected onto substrates through small-sized orifices, in particular, as in ink-jet printing, the orifices are easily clogged due to coagulation of the compositions.